Baffle wail



' Oct. 1, 1929. J. E. MUHLFELD BAFFLE WALL Original Filed Oct. 26, 19202 Sheets-Sheet l Oct. 1, 1929. J. E. MUHLFELD Re. 17,

BAFFLB WALL Ogiginal Filed Oct. 26. 1.9.20 2 Sheets-Sheet 2 INVENTOR@firzE/Vu/Zlfeld Ab: ATTOR EY' Reissued Oct. 1, 1929.

;ro'nu E. MUHLFELD, or soAnsnA E, new YORK BAFFLE WALL. I

Original No. 1,622,288, dated March 29, 1927; Serial No. 419,521, filedOctober 26', 192$). App1ication for reissue filed September .18,

This invention relates to bathe walls, and more particularly to: archwalls for the fire boxes of steam. locomotives, such, for instance as isshown and described inPatent No. 1,340,907, granted to me on May 5,1920. It will be observed upon referenceto my issuedpatent that thefurnace arch is made up of a. multiplicity of units or bricksofrefractory material. These bricks are arranged upon andsuspendedbetween the spaced water tubes. extending through thecombustion chamber and between the outermost tubes of the series and theinner side sheets of the furnace water legs. The outermost rows ofbattle bricks in the arch wall are differently formed or constructedatone of their ends from the intermediate bricks of the wall in. orderto provide for the proper engagement of the bricks in the outer siderows with the sheets of the water legs, or with suitable supportingmeans fixedthereto. It is, therefore, apparent that in the molding ofthe refractory bafflebricks or units it is necessary to have separatepatterns for the middle or intermediate bricks of the arch wall,

and for the bricks which constitute the outer sides of the wall. a Y

It is the primary object and purpose of my present invention to provideaba'lile brick or 39 unit construction for use in furnace arch wallswhich will enable the same mold pattern to be used for the outer rows aswell as the intermediate rows of bricks constituting the wallstructureso that the total number of brick patterns which it is necessary to keepin stock at therailway' storehousesrmay be substantially reduced by 50%.i y

I have found in actual practice that an arch wall having. all theadvantageous fea- 40 tures of the wall as disclosed in my issued patentmay beproduced with all of thebricks of identically the same form andconstruction by resorting to a very simple change in the formation ofthe brick or unit, whereby they may be arranged'in a substantiallycontinuous completely closed arch wall extending entirely across thecombustion chamber of the furnace between opposite side sheets, and suspended between said. sheets and the spaced series of water circulatingtubes. Since I am 1928. Serial No. 306,675.

thereby enabled to reduce the necessary num ber of brick. patterns asabove explained, it is apparent. that the costof production of thebaflie bricks or units willalso be appreciably reduced. y y I With theabove and otherobjects in view, the invention consists in the improvedcon' struction of the baffle brick or unit, as willbe" hereinafter morefully described,illustrated in the accompanying drawings, and.subsequently incorporated in the subj oined claims. In the drawings,wherein I have illustrated one satisfactory and practical embodiment: ofthe invention, and. in which. similar refer. ence characters designatecorresponding parts throughout the several views:

Figure 1 is a longitudinal sectional view through the fire box of alocomotive furnace,

showing a baffle or arch wall in which the presentimprovement isinccrporated.

' Figure 2 is a partial. transverse section through the watercirculating tubes andthe inner side sheets of the furnace water legs,illustrating the manner of arrangin o-r suspending the baffle bricks. orunits.

. Figure 3 is a top plan view of a portion of the baffle wall.

Figure 4 is an enlarged side elevation, partly in section, of one of thebafile bricks.

Figure 5 is an end elevation of the brick Figure 6 is a view similar toFigure 2 il lustrating an alternative form of the arch wall bricks orunits. I Figure 7 is a detailplan view of one of the bricks showninFigure 6: y y 0 Figure 8 is a view similar to Figure 4 showing one..ofj.tlie bricks on an enlarged. scale and partly in'section; I Figure 9is an end. elevation. of the alternative form of brick. Referringindetail to. thedrawings, where-. in I have illustrated a conventionaltype of locomotive furnace, 30 designates the combustion chamber andfire box of the furnace, which is provided with the usual grate 31, Thefurnace of the customary double wall construction 'is provided withwater. legs hav ing inner and outer side sheets '32 and 33 respectively,the water legs being extended across the frontof the furnace, as at 34,and

the inner sheets connected by the crown plate 35. The front wall of thefurnace structure is provided with the usual opening 36, through whichthe fuel is fed. Flues or fire tubes 37 are mounted in the rear end wallof the furnace in communication with the combustion chamber, and extendthrough the water space of the boiler. In addition to these tubes 37 aseries of transversely spaced water tubes 38 connect the front and rearwalls of the furnace structure, and are inclined downwardly from thefront to the rear wall so that the water as it is heated flows upwardlythrough these tubes from the rear to the front end of the combustionchamber.

In the present illustration I have shown three of the tubes 38, thoughany desired number of said tubes may be provided.

The bricks or units constituting the arch wall which issuspended fromthe tubes 38 are formed of refractory material. Preferably, these brickshave the configuration illustrated in Figure 4 of the drawings, and areproduced from the refractory material, while in a plastic condition, bymeans of a suitable mold. Thus each of the bricks is provided with aconvex lower face 41, which, when the bricks are arranged in assembledposition upon the tubes 38, has its intermediate portion disposed belowthe plane of the lowest surfaces of the tubes. The upper face of eachbrick is preferably, though not necessarily, recessed, as at Thelongitudinal side portions of the bricks for substantially the length ofthe recess or cavity 42 are of increased width to provide reinforcingribs or flanges 43 which constitute the opposite side walls of saidcavity. Upon the surface of the recess or cavity 42 suitable indicia 44is molded in the formation of the brick, such indicia denoting the typeand size of the brick in accordance with a legendary table upon whichthe different brick sizes are tabulated. It will be seen that the ribsor flanges 43 protect this indicia from wear, and possible obliterationwhen the bricks are piled upon each other for shipment. While I havefound this feature to be one of considerable practical convenience, itis, nevertheless, to be understood that the provision of such indiciamay be dispensed with, and that the brick need not necessarily beprovided with the side flanges 43.

Each of two opposite edges of the brick 40 is provided with atransversely extending seat 45 in the convex face 41, said seatingsurface being arcuately curved longitudinally of the brick upon a radiuswhich is somewhat greater than the radius of the water tube 38. It willthus be apparent that when the brick is arranged in suspended relationto the tube, the seating face 45 thereof will have a single point oftangential contact upon the periphery of the tube intermediate of theupper and lower edges of the seating surface.

Each edge face of the brick beyond the seating surface 45 is convexlycurved, as at 48, the radius of this curved edge face, the seat 45 andtube 38 having such relation to each other that when one edge of thebrick is engaged upon the upper side of one of the tubes 38 the bottomface of the brick will have contact upon the periphery of the tubeacross the entire width of the brick.

To the inner side sheets 32 of the water legs the spaced cylindricalsupporting trunnions ing faces 45 at one end of the bricks in this outerrow contacting upon the ends of the trunnions at the upper sidesthereof, the faces 45 extending inwardly and downwardly from the ends ofthe trunnions to the convex bottom faces 41 of the bricks.

As is well known in such locomotive furnace structures, the side sheets32 of the water legs are inclined both vertically and longitudinally,and have their upper portions curved inwardly to meet the crown sheet35. However, by providing the bricks 40 with the transversely convexedge faces 48 these edge faces will substantially clear the inner facesof the side sheets of the water legs so that the bricks may be easilyfitted in place or removed. The concave edge faces 45 of the brickprevent the pocketing of the products of combustion adjacent to thefurnace sides and the supporting trunnions below the brick and serve todirect such products either downwardly in part into the com- 7 bustionchamber, or to permit them to pass upwardly between the furnace sidesand the brick ends thereby obviating the possibility of slag formation,the deterioration of the brick or of the furnace sides by concentratedexcessive heating thereof.

The inner or intermediate rows of bricks are arranged in suspendedrelation between the adjacent tubes 38 with the convex edge faces 48 ofthe bricks in each of the rows opposed to the convex end faces of thebricks in an adjacent row, which are engaged upon the same water tube.The convex edge faces of the bricks in adjacent rows do not, however,contact with each other, and the bricks are at all times free andindependent, so that they can be separately removed and replaced at anytime. As the construction of the two opposite brick edges is identical,either edge of the bricks of the outer rows can be engaged with thesupporting trunnions on the water legs, and loss of time in fitting orassembling the outer rows of bricks inplace is thereby obviated. Thus itwillbe apparent that with a brick of this particular construction eitheredge of the brick may be properly positioned upon the water tubes 38 orupon the trunnions 50 so asto produce a substantially completely closedarch wall between the water legs. Therefore, in the production of afurnace arch of the type disclosed in my issued patent the' same brickpattern can be used for the mold of the bricks in the side rows. as wellas the bricks for the intermediate rows of the wall. Of course it isunderstood that the bricks may be pro duced in various lengths andwidths, and in the construction of the wall in many cases it isnecessary to use bricks of relatively short length in the outer siderows since the distance between the sheets 32 of the water legs and theouter tubes 38 is less than the distance between the adjacent watertubes. 1 1

However, even when the side brick are of different dimensions from theintermediate brickof the arch, since the means provided for engagementwith the water tubes and the trunnions or lugs on the side sheetspermits of the arrangement of the side brick between said lugs and thewater tubes regardless of the non-parallel relation between the sidearch tubes and the side sheets of the firebox, it is apparent that thecorresponding brick at the right and left hand sides oftlie arch may beinterchangeably used so that it is not necessary to make two differentlyshaped brick, one for the right and the other for the left side of thearch wall.

In this description, I have used the generic term edge with reference tothe parts of the brick which are provided with the concave grooves orseats a5, and it will be understood that these grooves will be formed ineither the side or end edges of the brick considered as an individualunit, depending upon the dimensions thereof. As illustrated in Figure 3of the drawings, with reference to the arrangement of the bricks withrespect to the water circulating tubes and the firebox side sheets, thegrooves or seats are provided in the side edges ofthe bricks extendinglongitudinally of the combustion chamber.

In Figures 6 to 9 inclusive ofthe drawings I have illustrated analternative embodiment of the invention, wherein each brick instead ofbeing provided with a convex bottom'face is formed with a flat or planesurface ll. The medial portion of the upper surface of the brick is alsoflat and disposed in aplane parallel with thebottom face 41, asindicated at 42. The under portions of this upper surface of the brickare convexas at 4%. In thisembodiment of the baffle brick, as in thepreferred form above describechthe transverse edge surfaces 48 arealsoconvex and the brick at each of its two opposite edges comparativelythin.

course, arranged upon the tubes and supporting trunnions 50'so that thebricks constitutupon the underside thereof is formed with, thetransversely extending longitudinally curved concave seating surfaces L5for engagement upon thesupports.

When the'bricks are arranged to form the battle wall structure as shownin Figure 6 ofthe drawings, the flat or plane bottom faces 41 thereofaredisposed in a common horizontal plane which is substantially'coincidentwith the horizontal plane of the axial centers'of the supporting tubes.Of course the bricks in the outer rows are arranged with their concavesurfaces 45 resting upon the supporting lugs on the side sheets of thewater legs- Since, in this alternativeembodiment of the invention, thebricks for the side and intermediate rows of the bafiie wall are all ofidentically the same form and construction, the same mold will serve forthe protection of both the outer and intermediate'brick and said brickof the side and interme diate rows will be freely interchange able. Thisalternative construction of the.

brick provides a very serviceable and practical baiflewall structure,which in many instances might be deslred 1n preference to a wallstructure as first above described, wherein the bricks are of such formas to produce the individual channels for thefiame and products ofcombustion along the underside of each water tube.

From theforegoing description considered in connection with theaccompanying drawings, the construction and several advantages of myimproved baflie brickwill be clearly understood. In my issued patentabove referred to I have illustrated numerous forms of bricks, all ofwhich have a common essential characteristic, namely, the intermediateportions of the. bricks project downwardly below the plane of the undersurface of the water tubes so that when the bricks are assembled and thewall structure completed, there is produced distinct longitudinallyextending channels along the underside of each water tube in and alongwhich the gases and products of combustion will undeviatingly flow fromoneend of the arch wall to the other. It is obvious that a wallconstructed of bricks of the form herein disclosed will possess the samedesirable attribute. The intermediate portions of the bricks againstwhich the flame and products of combustion immediately impinge, and bywhich they are directed towards thesides of the tubes isrelativelyythick so that the bricks will successfully withstand the highdegree of heat to which they are subjected. The ends of the owing to thecontinuous cooling effect of the circulating water, and may, therefore,be The bricks are, of

ing each longitudinal row have their opposed faces in close intimatecontact with each other, thus producing a substantially imperforate orclosed arch wall.

in the above description and the acco1npanying drawings I haveillustrated and described an embodiment of the invention which has beenfound to be very satisfactory in actual service. The presentimprovement, may, however, be incorporated in bricks of the severalforms disclosed in my issued patent, as well as in other alternativeembodiments of the brick construction. Accordingly, it is to beunderstood that I reserve the privilege of resorting to all suchlegitimate changes in the form, construction and relative arrangement ofthe several parts as may be fairly embodied within the spirit and scopeof the invention as claimed.

I claim:

1. In combination with a furnace combustion chamber having verticallydisposed water legs at the sides there-of andspaced wa- Y ter tubesextending longitudinally through said combustion chamber; an arch wall'consisting of bafiie units positioned in a common horizontal planeextending substantially entirely across the combustion chamber betweenthe vertically disposed water legs, spaced cylindrical supportingelements fixed to the water legs and projecting transversely therefrom,said units each having opposite edge portions of identically the sameconstruction and provided on the lower face of each edge portion with atube engaging surface adapted for close seating contact throughout saidportions of the unit upon one of said tubes or for seating engagementupon the upper side of one of said supporting elements, and each of saidedge portions of the baffle unit at the upper side thereof and abovesaid tube engaging surface terminating in an edge face having acontinuous convex curvature extending between the other opposite edgesof the unit whereby the side units of the arch wall may be properlypositioned upon said supporting elements and in close relation with theside sheets of the water legs.

2. In a locomotive fire box having verically disposed water legs at thesides thereof, and spaced water tubes extending through the combustionchamber; an arch wall consisting of baliie bricks all of identically thesame form and construction, supporting trunnions fixed to the sidesheets of the vertically disposed water legs, each bafile brick having atransversely extending longitudinally concaved seating face on its underside at each of two opposite edges thereof for continuous contact ofeach seating face between the other opposite edges of the brick upon oneof the water tubes, or for engagement with one of the trunnions, wherebysaid units may be arranged upon and between said tubes and between theoutermost tubes and the side sheets in a common transverse horizontalplane to provide a substantially closed wall.

3. A bafHe unit for locomotive fire box arches formed of refractorymaterial and provided at each of two opposite edges on the under sidethereof with a continuous uninterrupted surface extending across theentire edge of the unit for close seating engagement upon a watercirculating tube extending through the fire box or upon a supportingtrunnion fixed to one of the side sheets of the fire box, and each edgeof said unit above said tube engaging surface having a convex end facedescribing a continuous arc extending between the other edge faces ofthe unit.

t. A side arch brick for locomotive arches having similarly formed ends,each end being formed with an undercut groove adapted to engage asupporting tube, and being formed with a curved surface extending fromside to side and standing approximately perpendicular to the supportengaging portion of the groove.

In testimony that I claim the foregoing as my invention, I have signedmy name hereto.

JOHN E. MUHLFELD.

